gnome-post-install ordering

[Don Lewis]

I'm trying to debug why gtk-update-icon-cache isn't getting run when
the OpenOffice package is installed and ran into something that I don't
understand.

The Makefile contains INSTALLS_ICONS=yes, which has the side effect of
setting USES+=gnome, USE_GNOME+=gtk-update-icon-cache, and
_USES_install+=690:gnome-post-install, and that target is responsible
for parsing ${TMPPLIST} and invoking gtk-update-icon-cache as needed.
I do see gtk-update-icon-cache in the dependency list in +MANIFEST, so
it appears that INSTALLS_ICONS=yes is being detected.

It appears that things go wrong because I'm using the Makefile
post-install target to generate the plist.  If I look at bsd.port.mk, I
see that _STAGE_SEQ contains 700:post-install.  It looks to me like
gnome-post-install is getting run before the plist is generated, which
would explain why gnome-post-install isn't detecting any icons and not
invoking gtk-update-icon-cache.

Why is gnome-post-install earlier than post-install, which at least some
ports use to do plist generation?  Some ports do plist generation in
do-install, but that doesn't work if there are do-install option helpers
because those get run after the main do-install target.

There is the TARGET_ORDER_OVERRIDE knob, but it is very lightly used.